1. Field of the Invention
This invention relates to an apparatus for air conditioning a textile fiber processing line formed of a plurality of machines such as a bale opener, a mixer, a cleaner, a fiber tuft feeder, a carding machine and the like which are connected to one another by means of pneumatic fiber conveying ducts. Such a fiber processing line is typical in the field of spinning preparation.
2 Description of the Related Art
The apparatus is connected with an air conditioner for supplying conditioned air and further, the apparatus includes measuring sensors which are connected to the air conditioner by means of a regulating device and which respond to humidity and temperature conditions.
In pneumatic fiber tuft conveying systems the fiber material is advanced by a transporting medium such as an air stream through a conduit and is admitted to one or more machines, such as a fiber bale opener, a cleaner or a conveying machine or cards equipped with feed chutes. The machines are interconnected by a common conveying duct. The fiber material which is advanced in the conduit as fiber tufts does not have a constant behavior. Thus, it is a frequent occurrence that, for example, in branches or bends of the conveying conduit or at the inner wall faces thereof fiber tuft accumulations occur. This not only hinders the conveyance of fiber in the conduit but, in particular, prevents a downstream-arranged machine from uniformly receiving or further processing the fiber tufts or from uniformly charging, for example, a fill chute of a card with fiber tufts. In particular, the risks are high that a uniform deposition of fiber material in the fill chutes of cards is adversely affected by a pneumatic fiber tuft conveyance which takes place in upstream-arranged opening and/or cleaning machines. Such a disturbance, in turn, adversely affects the effort to maintain constant the sliver or yarn number of a sliver or yarn made of such a fiber material.
The appearance of undesired fiber accumulations in the pneumatic fiber tuft conveying systems is in most instances caused by electrostatic charges. Such charges are generated by friction when turbulences are present in the conveying air stream or by friction between the fiber tufts and the air stream as the fiber tufts are transferred into the conveying air from a processing machine or by friction of the fiber tufts among themselves. Because of the free flight of the fiber tufts in the conveying air stream, the electrostatic charge is not removed and thus remains present until the fiber tufts arrive into contact with an appropriate component which leads away the electrostatic charges. Accumulations of fiber tufts have been observed particularly in case of relatively dry transporting air. Excessive humidity in the transporting air or in the fiber material itself, however, results in a balling of the fiber tufts; this causes not only disturbances in the pneumatic conveying system but has a disadvantageous effect on the quality of the product made from the fibers.
In a known apparatus, in the pneumatic transport conduit in which the fiber tufts are advanced there are arranged a humidity sensor and a temperature sensor which are connected by means of a control device with a water vapor generator and with a heating device, respectively. Thus, a measuring of the humidity and temperature of the fiber tuft-charged air stream is taking place. It is a disadvantage of such an apparatus that the humidity and temperature of the fiber tufts themselves are measured indirectly; the conveying air serves as a medium. It is of particular disadvantage that the air stream is not steady but fluctuates in pressure and velocity.